Multiple work feeler safety control



Feb., 12, 1957 A. J. LANpA ETAL MULTIPLE WORK FEELER SAFETY CONTROL 2 Smets-sheet 1 Filed DBC. 22, 19541 Feb. 12, 1957 A. J. LANDA ETAL ZSm MULTIPLE WORK FEELER SAFETY CONTROL Filed DSG. 22, 1954 2 Sheets-Sheet 2 /III INVENTRS RHUR L LA/VA FRA/VK MMCDo/VALD A TTORA/Ex MULTWLE WRK FEELER SAFETY CONTROL Arthur .1. Landa, Huntington, Conn., and Frank H.

McDonald, independence, Mo., assignors to Remington Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware Application December 22, 1954, Serial No. 476,992

12 Claims. (Cl. 1-106) This invention relates to powder actuated tools, and

contemplates a hre control mechanism designed to in-h sure, as a condition precedent to tiring, the presence of a workpiece so positioned with respect to the muzzle as to receive and stop the explosively driven stud.

Tools of this character have the capacity for driving fastening devices into structural steel, and are well adapted for the securing to steel beams and purlins of fasteners for wall or roof covering sheets. The fastener projects outwardly from the purlin through a preformed hole in the sheet, and its free end is threaded or otherwise adapted to receive a tting which engages the exterior surface of the sheet. To drive the fastening stud into the purlin in proper relation to the hole in the sheet it is desirable to pass the muzzle of the stud driving tool through the hole and into Contact with the purlin. The driving tool is commonly so constructed as to require, as a prerequisite to tiring, that at least a part of the muzzle be firmly pressed against a purlin or other stud receiving workpiece, but when such contact is made through a hole in a covering sheet the hole may be so close to an edge of the purlin that there is inadequate metal in alignment with the tool to receive and stop the driven stud. Since the studs are expelled from the tool at high velocity, a ilying or ricochet stud in a substantial hazard to objects and persons in its path.

The present invention contemplates a stud driving tool provided with devices adapted to sense the presence of a solid surface in line with the entire perimeter of the tubular member through which the stud is delivered, and y to prevent tiring of the tool in the absence of a complete ring of solid material about the area to be penetrated by the stud.

ln the drawings:

Fig. 1 is a fragmentary side elevation, partly in section, showing one form of the invention and a typical form of ring mechanism adapted to be controlled thereby. The parts are in the normal position which they assume when a stud has been tired and the tool removed from the work. The work feelers are held retracted and the tiring mechanism is locked.

Fig. 2 is a skeleton view of some of the parts shown in Fig. l, the tire control means in an intermediate position in which the feelers are advanced and the tiring mechanism locked.

Fig. 3 shows the same parts as Fig. 2, the tool being pressed against an adequate work surface and thus unlocking the ring mechanism.

Fig. 4 is a fragmentary sectional elevation showing that the application of the tool to an inadequate work surface, such as the edge portion of a purlin, does not unlock the tiring mechanism.

Fig. 5 is a fragmentary horizontal section substantially on the line 5-5 of Fig. 4.

Fig. 6 is a transverse section substantially on the line 6-6 of Fig. 3.

Fig. 7 is a transverse section substantially on the line 7--7 of Fig. 2.

Patented Feb. 12, 1957 The tool comprises a barrel lil having associated with the breech end thereof a cartridge receiving chamber 11 adapted to be closed by a suitable breech piece or block 12. The stud to be driven by the combustion of the propellent powder of a cartridge in chamber 11 is suitably held in the barrel in front of the cartridge. The rearward portion of barrel 10 and associated parts may be enclosed within a housing 40. Typical firing means may comprise a striker 14 adapted to be driven against the proper part of the head of a cartridge by a spring 1S and held in cocked position against the thrust of spring 15 by a scar 16 adapted to be displaced to release the striker by a manually operable trigger 17. Movement of sear 16 to release the striker 14 is normally blocked (Figs. 1 and 2) by a scar lock 18 which is urged to effective position by spring 181, and it is only when sear lock 18 is displaced (by means to be described) to its Fig. 3 position that the scar can be displaced to enable the striker to perform its cartridge tiring movement.

To displace the sear lock 18 from its Fig. l position to its Fig. 3 position and thus permit ring, said sear lock is engaged by the end portion of a bar 191 which is one element of an integrated re control assembly identied generally by numeral 19. In the illustrative construction shown in the drawings, bar 191 extends forwardly in generally parallel relationship to the barrel 10, and is joined to a tubular member or sleeve 192 which surrounds the barrel and is urged forward (to- Ward the muzzle) relative to the barrel by suitable means, such as a spring 20.

The tool as above outlined is more fully described in the patent to Catlin, No. 2,669,716, February 23, 1954, but it will be understood that the invention about to be described is equally applicable to other tools of widely varying construction, the tiring mechanism in particular being susceptible to numerous modications. It is essential only that the ring mechanism include a control element capable of activation by the rectilinear movement of the tire control assembly 19.

l1`he forward end of sleeve 102 is joined to a second tubular member having a rear portion or barrel extension sleeve 193 which encircles the forward end of barrel 1i?, and a forward portion or barrel extension 194, which is of reduced exterior and interior dimensions. The bore of part 194 is substantially equal to the bore of barrel 10 and in tiring position (Fig. 3) acts as an extension of the barrel bore. In said tiring position, said barrel lll engages an O-ring 21 of compressible heat resistant material, said O-ring lying on a shoulder 22 at the junction of barrel extension and barrel extension sleeve, and sealing oft' powder combustion residues from the mechanism to be described.

Comparing Figs. l, 2, and 3, it will be seen that ring is possible only when the barrel 10 is fully advanced within the re control assembly 19 (comprising the integrated parts 191, 192, 193, and 194), as shown in Fig. 3. The barrel is normally moved to firing position by pressing the end of barrel extension rmly against the work, whereupon further movement of the tool toward the work will advance the barrel relative to the re control assembly 19. The present invention contemplates means which prevent full advance of the barrel to tiring position unless the entire circumference of the end of barrel extension 19d is solidly supported by the work. The embodiment of these means shown in the drawings is described as follows:

In the exterior surface of barrel extension 194 are formed a plurality of longitudinal grooves, six being illustrated, substantially equally circumferentially spaced. In each groove is a feeler 23, adapted to project outwardly beyond the end 195 of the barrel extension, as seen in Figs.

2 and 4. The several feelers and parts associated respectively therewith being identical, one only will be described. Each feeler 23 comprises an outward offset 231 adjacent the junction of barrel extension 194 and barrel extension sleeve 193, and beyond said offset occupies a longitudinal groove 196 in the periphery of said barrel extension sleeve. The inner end Aof each feeler 23 is in contact with a shoulder 242 of a blocking member 24 which occupies a widened extension of the groove 196 occupied by the feeler. Each blocking member 24 is urged toward its associated feeler 23 by suitable means such as a spring 25 which abuts the end of the groove 196 and may be partially received in a recess in its block 24.

Associated with each blocking member 24 is an aperture 26 through the wall of barrel extension sleeve 193. Each aperture is so placed with respect to its blocking member 24 as to be covered by the blocking member when the blocking member and its feeler 23 are thrust forward by the spring 25 (Fig. 2), and uncovered when pressure against the free end of feeler 23 maintains feeler and blocking member in the Figs. l, 3 and 5 position, compressing spring 25. It is again noted that there are a plurality of feelers 23, blocking members 24, springs 25 and apertures 26, and that each set of one of each of these elements is a unit which is entirely independent of any element of any other such unit.

In the outer surface of barrel is a peripheral recess 101, terminating in sloping or arcuate cam surfaces 102, 103, said recess preferably being of such length and so positioned that cam surfaces 102 and 103 traverse and pass beyond the set of apertures 26 in either direction as the barrel moves from normal (Fig. l) position to firing (Fig. 3) position. Within each aperture 26 is a ball or roller 27 having a transverse dimension greater than the depth of the aperture, that is, the diameter of the ball or roller is greater than the thickness of the wall of the barrel extension sleeve 193 at the location of apertures 26. Thus, each ball or roller must either lie partially within the barrel recess 101 or partially within the barrel extension sleeve recess 196 in front of its associated blocking member 24. Any ball or roller 27 lying partially within the sleeve recess 196 blocks movement of its member 24 to thrust feeler 23 forward, and any ball or roller lying partially within the barrel recess 101 blocks movement of the barrel to tiring mechanism releasing position (Fig. 3), as will now be more fully explained.

It will be remembered that barrel extension sleeve 193 is joined to and supports the firing mechanism unlocking bar 191. Fig. 1 shows the condition of the tool as it is removed from the work after tiring. The contact with the work necessary to enable tiring holds all feelers 23 in a rearward position, bringing their free ends substantially flush with the end 195 of the barrel extension. As the tool is withdrawn from the work, the thrust of relatively heavy spring maintains the tire control assembly 19 against the work as the barrel is retracted. Each of the feelers is thus held in a rearward position as the barrel retracts and each of the balls or rollers 27 is `cammed outwardly by the terminal cam face 103 of barrel recess 101, placing each ball in blocking position in front of its associated blocking member 24. Balls or rollers 27 are held in this position by their engagement with the unrecessed periphery of barrel 10, as clearly seen in Fig. l. Thus, when the tool is not in use the slender feelers 23 are retracted, housed and protected against damage.

Consider now that an attempt is made to manually retract the fire control assembly to firing position without engaging the tool with a work face. A relatively short movement of the tire control assembly brings barrel recess 101 opposite balls 27, whereupon said balls move into said recess, such movement being insured by their cam contact at 241 with blocking members 24, which members are now thrust forward by their springs and project feelers 23 outward, as seen in Fig. 2. Rearward movement of the re control assembly can be continued until balls or rollers 27 engage the terminal cam 102 of barrel recess 101 at which point it ceases, outward movement of balls or rollers 27 being blocked by blocking members 24.

If now the tool is pressed against an adequate work face in such a manner that all the feelers 23 and blocking members 24 are fully in rearward position, thus not blocking all apertures 26, each ball is cammed outwardly in front of its associated blocking member 24 and the movement of the barrel necessary to enable tiring can be completed. However, if any one of the feelers fails to find and be maintained in a rearward position by a work face (Fig. 4), or if the tool is tilted with respect to the work face so that any one or more feelers are not in a most rearward position with respect to housing 194, movement of the re control assembly remains blocked by the ball 27 associated with the incompletely displaced feeler.

A suitable sleeve 23-29 surrounds the barrel extension 194 and barrel extension sleeve 193, serving to hold the feelers 23 in place in their grooves. Preferably, a niufiler 30 surrounds and is secured to the first control assembly as shown, access from the bore to the muffler chamber being had through gas ports 31 in the barrel extension sleeve, preferably located forward of the O-ring 21 and aligned apertures in sleeve 29.

A cycle of operation of the tool will now be described. With the elements of the tool in their normal relation as shown in Fig. l, the end 195 of the barrel extension is pressed against the work surface. If all of the circumferentially spaced feelers 23 are supported by engagement with the work surface, continued pressure will cause barrel 10 to move downward in barrel extension sleeve 193, overcoming the resistance of spring 20, until the muzzle end of barrel 10 contacts the O ring 21 as shown in Fig. 3. Since the balls or rollers 27 are free to regress completely into housing 193 by reason of the blocking members 24 being maintained out of blocking position by the feelers 23, no obstruction is presented to movement of the barrel 10 to the tiring position shown in Fig. 3.

As previously set forth, movement of the barrel relative to housing 193 causes the sear lock 18 to be pressed back relative to sear 16 by engagement with bar 191, and as the barrel reaches firing position the sear is freed for subsequent operation by pressing the trigger.

if, in the just described cycle of operation, one or more of the feeler rods 23 is not supported by a portion of the work surface, that unsupported feeler will project in advance of end 195 and the associated blocking member 24 under the urging of spring 25 will move behind ball 27, causing the ball to protrude into peripheral recess 101 where it engages terminal cam 102 blocking advance of the barrel to ring position. It will be seen that each of the feelers must engage with a portion of a work surface before the tool may be red.

What is claimed is:

l, In a powder actuated tool having a barrel and breech assembly, means on said assembly for ring a cartridge in said barrel and means normally locking said ring means, the invention consisting of a fire control member .surrounding said barrel and having a work engaging end in advance of said barrel muzzle, said barrel and breech assembly being reciprocable in said member from a normal retracted position to a predetermined advanced firing position, means on said member for disabling said locking means when said assembly is in ring position, a plurality of independent latching devices mounted in said member for engagement with said barrel, each of said devices being capable of blocking movement of said assembly to ring position, and a plurality of latch controlling feelers `mounted in said member for engagement with a work surface, each of said feelers being independently movable when unsupported by a work surface to release a respective latching device for engagement with said barrel.

2. A tool according to claim l, in which each of said latching devices comprises a locking element disposed for radial engagement with an interrupted surface on said barrel, a reciprocable blocking member disposed to displace said element into locking engagement with said interrupted surface at one extent of reciprocation and spring means urging said blocking member towards engagement with said element, one of said feelers supporting said blocking member out of engagement with said eiement against said spring when said feeler is supported by a Work surface.

3. A tool according to claim 2, wherein said interrupted barrel surface comprises a peripheral groove joined to the main barrel circumference by opposed camming surfaces, said groove being disposed to traverse said locking elements when said barrel is reciprocated, whereby in barrel reciprocation each blocking member unsupported by a feeler will force an associated element into locking engagement in said barrel groove, and said camming surfaces will force each of said elements out of locking engagement when all of said blocking members are supported by feelers.

4. A tool according to claim 3, in which said blocking members normally prevent displacement of said locking elements respectively by said cam surfaces, thereby preventing movement of said barrel to firing position.

5. A tool according to claim 4, in which support of each feeler by a Work surface to a predetermined position so displaces the associated blocking member as to enable displacement of the associated locking element out of the path of movement of said barrel cam.

6. A tool according Ito claim 5, in which incomplete displacement of any of said feelers and its associated blocking member is effective to prevent movement of said barrel relative to said fire control member to said iii-ing position.

7. A tool according to claim 6, comprising means associated with said barrel adapted to displace said blocking devices to lock said feelers in retracted position when said barrel is in normal position with respect to said fire control member, and to release said feelers for forward ydisplacement by said spring means respectively when said barrel is displaced from normal position toward firing position.

8. A tool according to claim 1, in which said tire control member comprises a tubular feature surounding said barrel and having a work engaging end disposed in advance of said barrel muzzle, said feelers being mounted in longitudinally extending grooves formed on the exterior surface of said feature.

9. A ltool according to claim 8, in which said lire control member comprises a tubular feature having an eX- tension of lesser diameter than said feature extending in advance of said barrel muzzle, said feature and said extension being provided With a plurality of longitudinal grooves to slidably accept said feelers, each of said feelers having an oifset intermediate portion substantially equal in length to the difference in radii between said tubular feature and said extension.

l0. A tool according to claim 8, comprising a cylindrical cover surrounding said tubular feature `and said feelers.

ll. A tool according to claim 9, comprising a conforming cover for said tubular feature and said feelers, a muffler mounted on said cover, and access ports between the interior of said tubular feature and said mufer.

12. A tool according to claim l1, in which said Ilire control means comprises a barrel extension sleeve and a barrel extension of lesser diameter than and joining said sleeve in a shoulder, a sealing gasket on said shoulder adapted when engaged by said barrel to seal the interior of said barrel extension sleeve from the interior of said barrel and said barrel extension, said access ports establishing a passage from said barrel extension to said muler.

References Cited in the tile of this patent UNITED STATES PATENTS 

